The patent dispute between Oracle and Google about the alleged infringement of copyrights by the open source Android mobile operating system is going into the next round. In its answer to the responsible court, Google denies Oracle's allegations that the Android OS infringes Java patents and copyrights owned by Oracle. Writing to the US District Court for the Northern District of California, Google denies the alleged infringement of seven patents and asks the presiding judge to invalidate the patents in question.

Oracle, who took on the patronage of Java with the take-over of Sun, had filed a patent and copyright infringement complaint against Google on the 12th of August. Google uses a free Java implementation – Apache Harmony – as the run-time environment for its Android operating system and has remodelled it into the Dalvik virtual machine. The company has been accused of violating patents number 6,125,447, 6,192,476, 5,966,702, 7,426,720, RE38,104, 6,910,205 and 6,061,520, which were originally granted to Sun. Oracle claimed that Google "knowingly, directly and repeatedly infringed Oracle's Java-related intellectual property" in developing Android.

Google now accuses Oracle of attacking its own previously established open source strategy with these claims. "It’s disappointing that after years of supporting open source, Oracle turned around to attack not just Android, but the entire open source Java community with vague software patent claims”, said a Google spokesperson. For instance, Oracle had previously criticised Sun for not releasing the official "Test Compatibility Kits" (TCK) under an open source licence. However, Google says, since acquiring Sun, Oracle has ignored requests from the open source community to fully open source the Java platform.

The 27 page document continues to say that Sun specified the Java Virtual Machine (JVM) in such a way that developers can create custom implementations, and that Google created such an implementation with the Dalvik VM. Google is of the opinion that its mobile operating system is important for the Java open source community and for promoting the popularity of the Java programming language. To support this opinion, the vendor states that there are now around 90 Android devices by about 20 vendors, and that about 200,000 Android smartphones are activated every day.

Oracle's response was swift. Deborah Hellinger, Oracle's company spokeswoman, said that Google, when developing Android, chose to use Java code without obtaining a licence. "Additionally, it modified the technology so it is not compliant with Java’s central design principle to 'write once and run anywhere'. Hellinger said Google’s infringement and fragmentation of Java code not only damages Oracle, it clearly harms consumers, developers and device manufacturers".